56 Speciication by Example

Speciication by Example provides artifacts around requirements—living documen- tation—that can be used for traceability. This enables agile processes to be applied to regulated industries. Bas Vodde and Craig Larman wrote about the irst agile development project in the U.S. nuclear industry6 in Practices for Scaling Lean and Agile.7 The team working on that project used executable speciications to ensure full traceability of requirements, which is critical in nuclear and other safety-critical domains. On the other hand, because of a highly dynamic, iterative, and collaborative approach to building these artifacts, up-front sign-off is practically impossible. Here are some ideas on how to deal with sign-off and traceability constraints.

Keep executable speciications in a version control system

Many automation tools work with executable speciications in plain-text iles, so they work nicely with version control systems. This allows you to easily tag and branch the speciications along with the source code. It gives you a current and correct version of tests that can be used to validate any version of your product.

Version control systems are great for traceability because they allow you to ind who changed any ile, when, and why in an instant. If you store your executable speciications in a version control system, you’ll get traceability on requirements and speciications for free. With Speciication by Example, the executable speciications will be directly linked to the programming language code (through the automation layer), which means that it will be relatively straightforward to prove code traceability as well.

Executable speciications in a version control system are also less likely to disappear than those stored in a separate requirements or test tool.

Get sign-off on exported living documentation

When: Signing off iteration by iteration

Speciication by Example should help build trust between project sponsors and the delivery team and remove the need for sign-off. If you do need to get requirements signed off for commercial or political reasons, you can use the living documentation system for that.